Category: Diseases and Disorders

HYPP horses need low potassium diets when compared to “normal” horses – less than 1% potassium in total diet including hay + grain. But, a percentage in a feed is really only a percentage and doesn’t tell you what you really need to know – which is, how much potassium your horse is actually getting in the total diet. This number will depend on the percent of potassium in each feedstuff, and how much of each feedstuff is being fed.

Hay Selection: Hay makes up the majority of the diet so typically contributes the most potassium. It’s best to have your hay tested if possible, but if you can’t do that, keep in mind the following:

Oat hay and grass hay are the lowest in potassium

Orchard grass is high in potassium so stay away from that.

Feed Selection:

Textured/whole grain based feeds tend to be lower in potassium then pelleted feeds, since whole grains are naturally low in potassium, where some ingredients used in pellets tend to be higher potassium sources.

“Sweet” feeds may or may not use a lot of molasses, which is high in potassium. The “wetness” of a sweet feed may come from vegetable oils rather than molasses, so don’t automatically rule sweet feeds out.

Some pelleted feeds can be a good choice if the horse is N/H and doesn’t have many episodes, but may not work for horses that are H/H and have severe or many episodes.

Higher fat and calorie feeds may allow you to feed less, and this can lower total potassium as well when you can feed less to maintain body condition.

Do not feed electrolytes containing potassium.

Do not use high levels of cane, molasses, or bran mashes because they may be high in potassium.

Doing the math: To determine how much potassium is in your HYPP horse’s total diet, you’ll need to do some good old fashioned math!

From this example, the horse should do well on this diet. If the horse can maintain body condition on less hay or grain, or if the hay tested lower in potassium, then that would be less potassium in the total diet as well.

Other Considerations:

Starch Intake: It is a misconception that HYPP horse need low starch. They actually need sufficient starch as a source of glucose, because glucose stimulates the release of insulin and this promotes potassium uptake by the cells.

Management: HYPP horses should be turned out as much as possible and/or placed on a regular exercise program.

This article is courtesy of Krishona Martinson, PhD, University of Minnesota.

Soaking hay in water is a common strategy used to manage the nutrition of some diseased horses. Current hay soaking recommendations include soaking hay for 30 minutes in warm or 60 minutes in cold water for removal of carbohydrates (Watts, 2003). Soaking hay is commonly done to manage horse diagnosed with laminitis, Polysaccaride Storage Myopathy (PSSM), hyperkalemic periodic paralysis (HYPP), and chronic obstructive pulmonary disease (COPD).

However, how efficient is hay soaking, and are additional essential nutrients lost during the soaking process? Researchers at the University of Minnesota set out to determine the impact of water temperature and soaking duration on removal of NSC, crude protein (CP), minerals, and dry matter (DM) from alfalfa and orchardgrass hays.

Four hay types were soaked, including bud and flowering alfalfa, and vegetative and flowering orchardgrass. Individual flakes were submerged for 15, 30 and 60 minutes in 25 liters of cold (72°F) and warm (102°F) water, and for 12 hours in cold water. A control (non-soaked) sample was also evaluated. Water temperatures were determined by using the cold or warm only faucets, similar to practices implemented by horse owners and managers. Subsamples of entire flakes were submitted for nutrient analysis at a commercial laboratory.

Prior to soaking, both alfalfa hays were below the 10 and 12% NSC threshold for horses diagnosed with PSSM and laminitis, respectively, and would not have required soaking. The orchardgrass hays were above these thresholds, however, after soaking for 15 to 30 minutes were at or below 10 to 12% NSC.

Although soaking hay for longer durations did further reduce NSC content, it is not recommended. All horses, even diseased ones, require carbohydrates in their diet.

The severely limited NSC content in hay soaked for greater than 1 hour, combined with increased fiber amounts (fiber components are not water soluble, thus they are concentrated in soaked hay), brings into question the palatability and availability of nutrients in hay soaked for longer periods of time.

Crude protein leaching was variable in soaked hays, something other researchers have also observed (Moore-Colyer, 1996). More importantly, previous research looked at the nutrient availability and quality of rained-on hay fed to steers and suggested the nitrogen remaining in rained-on hay is more stable, water-insoluble (Rotz and Muck, 1994), and possibly less digestible by ruminants (Licitra et al, 1996). Additional research is needed to evaluate this concept when feeding soaked hay to horses.

Calcium (Ca) is not as prone to leaching during soaking compared to other minerals, and appears to be dependent on hay maturity. As soaking duration increased, leaching of Ca increased in alfalfa bud and vegetative orchardgrass hays (immature hays). However, soaking had no effect on Ca leaching in the more mature hays.

Conversely, magnesium (Mg) Mg and phosphorus (P) levels were reduced in all hay types as a result of soaking, with longer soaking durations leading to greater reductions. Because Ca is not as water soluble as P, high Ca:P ratios were observed in hays soaked for longer durations, specifically after 12 hours.

Ideally, Ca:P ratios should range from 1:1 to 3:1 (up to 6:1) in horse diets (NRC, 2007). The high Ca:P ratios observed after longer soaking durations were exaggerated in alfalfa hays which had higher Ca:P ratios prior to soaking.

After 12 hours of soaking, a deficiency in P was observed and ranged from a shortage of 1 to 8 grams for a 500 kg horse in light work (NRC, 2007), and Krook and Maylin [32] suggested that osteochondrosis may be associated with excess dietary Ca.

Soaking both alfalfa and orchardgrass hay for 12 hours was necessary to sufficiently reduce K concentration to recommend levels prior to feeding horses diagnosed with HYPP (Reynolds et al, 1997). Although K levels can be reduced by soaking, neither alfalfa nor orchardgrass hay is an appropriate option for horses diagnosed with HYPP due to the naturally high levels of K.

Owners should rely on forage analysis as the primary method of determining the appropriate hay for horses, especially when feeding horses diagnosed with laminitis, PSSM, HYPP or COPD. Hay soaking for short durations (15 to 30 minutes in duration) is an acceptable management method, but should only be used if ideal hay is not available. Hay should not soak hay for greater than 1 hour. Soaking hay for long durations resulted in severely reduced NSC content, high Ca:P ratios, shortage of P in the diet and significant losses in DM.

There are a number of potential illnesses which can cause horses to go “off feed” for varying periods of time. Upper respiratory issues, such as strangles and influenza, may cause the horse to lose appetite and reduce feed intake.

There is a bit of a trade off with the nutrient requirements of the horse that is off feed due to illness. On one hand, the horse may be moving around less because it does not feel good, so it is not burning up as many calories. On the other hand, immune response and maintaining/building new tissue requires adequate Calorie intake, along with amino acids, minerals and vitamins, and adequate water intake. There is also a difference between a healthy horse that is experiences reduced feed intake, and a sick horse that experiences reduced feed intake. The body of the healthy horse conserves resources, while the sick horse has to expend resources to get well.

The following steps may be useful for the horse that is experiencing reduced feed intake due to fever or upper respiratory issues:

Horses with a contagious condition such as strangle or influenza should be properly isolated with appropriate biosecurity measures to prevent the spread to other animals. Biosecurity is a separate topic and is very important.

Palatable forage should be used. If a horse already has a respiratory issue, care should be taken to make sure the forage is dust free. It may be dampened or soaked if needed.

A palatable well fortified feed should be used to help maintain intake and provide the nutrients required to support immune response and healing, particularly adequate amino acids, trace minerals and vitamins. Anti-oxidants such as selenium and Vitamin E may be useful.

A feed with added fat may provide easily digestible Calories with reduced risk of metabolic disturbances.

The goal should be to support the horse during the illness, and minimize weight loss and muscle wasting.

Regardless of the age of the horse, a senior horse feed may be a good option. Senior horse feeds are very safe, highly digestible, highly palatable and well fortified. They are designed to be used as complete feeds or with limited forage intake and can be made into a mash if needed. They work well for many recovery conditions.

If a horse is in training, care must be exercised in that even a few days of stall rest can result in some loss of bone density and soft tissue strength, so training needs to be adjusted accordingly to reduce the risk of injury. Also, lung function may not be back to 100% for several weeks following a respiratory infection.

Horses that are ill, and particularly ones that are severely emaciated, should be under the direction of a veterinarian.

The vet has diagnosed it and the reality begins to sink in – your horse has Cushing’s disease. Now what? Cushing’s is an endocrine disease caused by a tumor on the pituitary gland that is most often seen in older horses and ponies. This tumor results in high cortisol and is most often exhibited by hyperglycemia (high glucose), excessive thirst, excessive eating, excess urination and a shaggy haircoat. At this time there is no cure for Cushing’s but by keeping a close eye on nutrition and management, we can improve the quality and possibly lengthen the life span of a Cushing’s horse.

Routine is important to the Cushing’s horse because changes in diet, medication, etc. can have negative effects on health. Cushing’s horses have a compromised immune system and for that reason, seemingly small or mundane parts of their care become very important. There are a few management practices that are particularly important:

Deworming – Cushing’s horses can be more susceptible to parasites because of their weakened immune system. Work closely with your vet to develop a deworming schedule and program that is catered to your horse. Your vet should also be seen regularly for dental care and wellness exams.

Farrier Care– Regular farrier visits are important because certain types of leg and foot conditions are more likely with a Cushing’s horse, such as abcesses of the hoof and laminitis. Signs of laminitis can be a tender footed stance and the horse acting like he is “walking on egg shells”.

Grooming – Hair coat and temperature regulation are problems in Cushing’s horses so you will want to help your horse as much as you can by preventative grooming practices. Consider body clipping in hot/humid weather and be mindful of temperature and weather changes. When blanketing, make sure the hair coat is dry and clean to help reduce the incidence of skin issues. Prompt treatment of any wounds or infections is essential.

Feeding– One of the main goals in feeding the Cushing’s horse is to control the starch + sugar (NSC) content per meal. This helps to regulate the blood glucose and insulin levels. The NSC content of the concentrates fed to the horse is important, but even more so is the content of the hay /forage and the combination of the two together. Some guidelines have suggested an NSC maximum value of 10-13% based on the total diet (forage + concentrate). Testing your hay will give you a good idea of the NSC values.

Consider a feed that is fortified with lysine, methionine, biotin, vitamin E and complexed trace minerals (copper, zinc, manganese and selenium) to help maintain muscle mass, support hoof growth and support the immune system.

Following these tips will help improve the quality and possibly length of life for the horse diagnosed with Cushing’s. If you have specific questions regarding your horse, please work with a qualified nutrition consultant or your veterinarian.

Previously, I introduced you to George, my ‘Heinz-57’ PSSM positive horse. Though his test results came back positive for Type 1 PSSM, his diagnosis does not mean his athletic career is over. With some diligence and routine, George is able to lead a normal life as a successful working partner.

One key to managing his condition is maintaining consistency in his diet and routine. Remember, he would get sore every time the hay changed, particularly if it had alfalfa in it. First I work to ensure that George’s total diet is properly balanced which starts with controlling the starch and sugar energy sources in his hay and grain ration. I buy larger quantities of grass hay (no alfalfa) that will last awhile, a full year if possible. I also have my hay tested before buying it to make sure it isn’t too high in non-structural carbohydrates (12% NSC or less), and that the rest of the nutrients are within an acceptable range for good quality hay, as this is the bulk of his diet. The lower the NSC in the hay, the more room there is in the diet to add calories from fat. More on that below.

To balance his hay, he gets a controlled starch feed concentrate that is fortified with essential amino acids, complexed trace minerals, pre- and probiotics. If I need to add calories to his diet to support higher levels of exertion during training and show season, I add a balanced fat supplement to the concentrate component of his diet. To meet the total caloric requirement it is recommended that PSSM positive horses receive no more than 10% of the digestible energy from non-structural carbohydrates (starch and sugar), and 15-20% of the digestible energy should be supplied by fat. Remember, this applies to the total diet, contributions from grain plus forage. Working with a qualified equine nutritionist is a great way to figure all of this out. In a nutshell, I control the sugars and starches in his total diet (low NSC grass hay and low calorie, controlled NSC grain) and add a nutritionally balanced fat source when extra calories are needed. The only supplement he gets is vitamin E, which helps boost his antioxidant status (helps fight oxidative stress), and supports muscle recovery after exercise. Because his total diet is balanced for selenium, I don’t supplement this mineral to avoid potential toxicity.

Estimating his weight and doing a regular body condition score help me adjust his diet and exercise routine accordingly, so he maintains good muscle mass and avoids excess fat deposits. In addition, I make sure to minimize stress as much as possible by keeping his routine consistent. His daily ration is divided up into 3 meals to avoid one large grain meal and he has access to hay for most of the day. He gets a minimum turnout of 8 hours every day with a buddy and limited access to fresh forage. I also exercise him at least 6 days a week. With this management routine, regular veterinary and farrier care, he has never “tied-up” on me, and continues to excel in dressage with the occasional hunter pace thrown into the mix. Providing good quality of life is a top priority, especially when it comes to managing even the most challenging horses, and I think George would agree, he is doing great!

I’m proud to introduce you to George, a “Heinz-57” draft cross, and my current equine partner. He is the result of a ½ Thoroughbred, ½ Percheron (dam) x ½ Hanoverian, ½ Paint horse (sire). I’ve had the privilege of knowing George since he was a weanling, and bought him as a yearling. It wasn’t until I started him under-saddle as a three and a half year old that I started noticing behavioral changes (crankiness – not like George), non-specific muscle soreness, and a transient, almost undetectable gait abnormality, all of which happened to be associated with new hay delivery. I won’t mention how much I’ve spent having him worked-up, imaged, adjusted, fitted and many more things to get to the bottom of what his body was trying to tell me. We were coming up empty handed and frustrated.

It wasn’t until after I returned from an equine nutrition symposia that it occurred to me to have him tested for polysaccharide storage myopathy (PSSM). PSSM causes the horse’s muscle cells to store energy (glycogen) in excess, which can result in a variety of symptoms, the most severe of which is tying up after aerobic exercise. Nearly all of the classic signs were there, short of a bad tying up episode. Wouldn’t you know it, he came back positive for Type-1 PSSM a.k.a. EPSM, tying- up syndrome/exertional rhabdomyolysis/Monday morning disease, set fast or azoturia. There is more than one version of PSSM (Type-1 is most common) and the diagnostic tests for each are unique.

Recent advances in equine genetics have made testing a blood, muscle, or hair follicle sample possible. As it turns out, three of the four breeds that George represents have been identified as prone to carrying the genetic mutation responsible for PSSM. Unlike some other recessive genetic diseases, PSSM is inherited as a dominant gene; in other words having just one copy of the mutated gene means the horse has the disease. Horses lucky enough to inherit 2 copies of the gene can be more severely affected. The good news is, with a little diligence, these horses can be managed and go on to have a good quality of life and successful athletic careers; both of which I want for George.

Work with an equine nutritionist or veterinarian to understand what a healthy weight and body condition is for your horse to help prevent over-feeding or dietary imbalances that can contribute to EMS.

For horses who already are dealing with EMS, follow these tips to help successfully manage their condition:

Prevent or reduce obesity through controlled starch and sugar in the total diet along with exercise (unless horse is painful from laminitis episodes).

It is recommended that these horses have very little to no access to fresh pasture to avoid the overexposure to the sugars in grass. Use of grazing muzzles or a dry lot are good alternatives to stall confinement, as this allows the horse to exercise on its own.

Have a nutrient analysis done on your hay to understand the NSC content – keeping in mind that it is important to understanding to NSC content of the total diet (hay + grain, if applicable).

Soaking hay (15 – 30 min warm water) can help leach out some of the sugars in the hay, just be sure to feed the hay right away before it spoils, and discard the sugar waste water, so the horse does not have access to it.

Low calorie ration balancers are good horse feed options to balance the diet if there are vitamin and mineral deficiencies from feeding a forage only diet, and/or from soaking hay.

EMS is an endocrine (hormonal) disorder in horses, similar to metabolic syndrome in humans, that is characterized by obesity, insulin resistance, and regional adiposity (abnormal fat deposits), which can predispose affected horses to chronic laminitis.

What types of horses are affected?

First and foremost, most horses do not suffer from EMS. Most horses tolerate dietary carbohydrates (e.g. NSC, starch, sugar, fructan) quite well, and thrive on this important and readily available source of energy. Performance horses in particular need sufficient NSC in their diets for work and recovery after exercise. Too little starch and sugar in the diet can actually diminish athletic performance over time in non-EMS horses.

Tess the pony indulges

That being said, EMS can occur in any breed, however ponies, Morgans, Paso Finos, and horses that tend to be “easy keepers” seem to be most vulnerable to developing EMS. It should also be noted that not all obese (fat) horses are insulin resistant, and not all insulin resistant horses are fat.

How do I know if my horse is insulin resistant (IR)?

Veterinary diagnostic testing (blood work) is recommended to confirm IR, but here are some other classic signs of insulin resistance in horses and ponies:

A classic sign of IR is a “cresty neck”, of which a clear correlation between neck circumference and IR has been documented.

Horses with regional deposits of lumpy or dimpled fat pads (e.g. behind the shoulder, around tailhead, over the loin), are suspect of being IR.

Horses that seem to gain weight rapidly, or blow up easily, particularly in spring with new pasture growth, relative to other horses may indicate IR.

Horses that are tender footed, and/or that demonstrate rings on the hoof wall, expanded white line and blood spots on the soles of their feet, suggests mild, chronic bouts of laminitis and IR.

EMS is easily confused with other clinical disease such as Cushing’s Disease (a.k.a. pituitary pars intermedia dysfunction) and hypothyroidism due to similar clinical signs, despite different underlying causes. It is very important to work with a trusted vet to ensure an accurate diagnosis if any of these conditions are suspected.

A word of caution, single blood samples for the diagnosis of IR can be very unreliable and misleading as several factors unrelated to EMS influence glucose and insulin levels (time and content of horse’s last meal, type of feed horse is adapted to, time of day sample is collected, stress level of horse), leading to false conclusions. Taking multiple blood samples over several days, or utilizing techniques such as the euglycemic insulin clamp or a combined glucose insulin tolerance test (CGIT) are more involved, but can lend more validity to the lab analysis. In any case, early detection of EMS and other endocrine disorders is preferable.

Laminitis in short, is the inflammation of soft tissue in the hoof causing damage to or death of the laminar cells, resulting in the loss of the foot’s mechanical integrity. The severity of damage is unique to each case with the worst damage resulting in founder which is the sinking of the coffin bone.

Overall management and feeding of horses with laminitis requires special care, since factors such as body weight, starch intake, mineral and energy balance, as well as metabolic function can have a profound effect on the fragile environment of the damaged tissue of the hoof. If you are managing a horse currently being treated for laminitis or one with a history of laminitis, the most important element of overall care is staying connected to your vet and farrier. When it comes to feeding, here are some nutrition tips to help you along the way.

Weight: weight control and regular exercise help any horse physically and mentally, but the laminitic horse in particular. Excess weight and stagnation add unneeded stress to an already fragile situation. Once the acute phase has passed, regular turn out and exercise provide essential blood flow to the foot, which provides the nutrients for tissue repair. Activity is also helpful in managing weight.

Pasture: Lush pasture access should be limited by a grazing muzzle for horses prone to laminitis or those currently being treated for it. If a grazing muzzle is not available, the horse should be limited to access later in the day when plant sugar (fructans) levels in grass are lower, or be kept on a dry lot.

Forage: High quality grass hay is the ideal forage for a horse prone to laminitis.

Feed: A product specially formulated for metabolic issues or a ration balancer are the best bet to feed your laminitic horse. Micro nutrients such as vitamins and minerals are essential for tissue repair, so be sure to check that the feed is balanced for these as well as the essential amino acids. Avoid feeds which provide high levels of starch per meal as these horses tend to be sensitive to increases in blood sugar and insulin.

Supplements: Horses with laminitis may benefit from supplemental magnesium and chromium, both of which assist in sensitivity to insulin.

Water: Often overlooked as a nutrient, water is one of the best allies in the defense of laminitis in your horse. Fresh, clean tepid water is a key to overall health as well as circulation of nutrient rich blood.

Following these guidelines for feeding and management, as well as working closely with your veterinarian and farrier should provide you with the tools you need to manage laminitis in your horse. With extra care and help from the trusted professionals in your life, your horse with laminitis can live a happy, balanced life.

If your horse has ever had issues with his/her feet, the old adage, ‘no hoof, no horse’ could not ring truer. When considering hoof health, multiple factors influence the state of your horse’s feet including nutrition, conformation, environment, use and overall management and care. When assessing your nutrition program in relation to hoof health, there are many key components that need to be present for healthy hoof maintenance and growth.

Water is the most important nutrient for horses overall. Specifically for feet, adequate amounts of water provide tissue hydration and promotes the circulation needed to deliver nutrients to the living hoof tissues.

Balanced energy in the diet is important to support metabolic activity, the growth and function across the entire body system, including the feet.

Balanced proteins (aka amino acids) provide structural strength and function for hoof tissues. Lysine, Methionine and Threonine are the three most commonly associated with hoof growth. It is imperative that amino acids be present in balanced levels along with key minerals and vitamins. The ability for the body to absorb these critical nutrients is dependant on the delicate balance of them and too much of one or another can disrupt the utilization of these key nutrients.

Micro minerals (aka trace minerals) include zinc, copper, manganese, cobalt, selenium and more. Trace minerals help with the synthesis of proteins, immune system activity, synthesis and maintenance of elastic connective tissues, the integrity of skeletal bone tissue, antioxidant activity and much more.

Vitamins, both fat and water soluble, play a key role in the formation, maintenance and repair of hoof tissues. Vitamin A,D and E aid in bone and muscle growth, maintenance of healthy epithelial tissue, calcium metabolism control, immune response and activity. Vitamins C and B-biotin, both water-soluble vitamins, aid in antioxidant activity, lipid metabolism, as well as growth and maintenance of tissues. Biotin aids in the cell-to-cell adhesion in the outer hoof layer.

If you are feeding a commercially produced complete feed, check the guaranteed analysis for these nutrients. It is also important to check that you are following the feeding directions so the proper levels of nutrients are making it in your horse. Feed companies formulate the nutrient density and balance based on their feeding directions. Feeding less than recommended amount means your horse is likely not getting enough of the balanced nutrients he needs.

Hoof supplements are widely available and varied. If you are feeding a complete feed from a commercial manufacturer that guarentees levels of the nutrients listed above, you likely do not need to supplement for hoof quality. However, special cases require additional nutrient supplementation. It is best to work with your vet, farrier and a qualified nutrition consultant to determine the best feed and supplementation program for your horse.

Feeding a horse that has established foot issues such as laminitis takes special care, as he needs the nutrients in feed but likely not the energy provided. Excessive levels of starch and sugar per meal increase spikes in glucose and insulin which may have a negative impact on feet. A low calorie feed or ration balancer fully fortified with vitamins, minerals and amino acids is your best bet for these special cases.

Finally, if you have specific questions about your feeding program, check with a qualified nutrition consultant for more information. A combination of regular hoof care , the right nutrition and proper management for your horse will go a long way in keeping him or her sound for years to come.